Channel Coupling Research Articles

Capacitive coupling memristive systems for energy balance

The dynamics of a memristive system is dependent on the initial values and thus the threshold of coupling intensity for synchronization approach becomes unknown and unpredictable. Joule heat is consumed before reaching complete synchronization when variable coupling is applied for triggering voltage coupling via resistor connection. In this paper, a capacitor is used to couple two memristive circuits and the coupling intensity is increased in exponential way until the two memristive systems reach energy balance adaptively. The regulation of coupling intensity is controlled by using the Heaviside function when the Hamilton energy functions for the memristive systems are available. It is confirmed that two memristive systems can reach complete synchronization, phase lock when the coupling intensity is regulated in an adaptive way. It also explains why energy diversity enables creation of channel connection and coupling between nonlinear circuits, and then the coupling channel is tamed to realize energy balance between memristive systems without confirming exact threshold for coupling intensity. The scheme shows distinct self-adaptive property because the coupling intensity is controlled by the energy flow along the coupling channel. In particular, this kind of field coupling is controllable and external energy injection is helpful to regulate the coupling channel adaptively.

О технических методах снижения числа сбоев в работе основных локомотивных устройств безопасности

Violations in operation of receiving equipment of safety locomotive major devices due to the hindering effect of electromagnetic interference (failures) are a rather frequent phenomenon on the railway network of the Open Joint Stock Company «Russian Railways» in the conditions of electromagnetic environment that has changed dramatically with active introduction of modern electric rolling stock. On the one hand, failures are the result of discrepancy of own parameters and operation algorithm of receiving equipment of safety locomotive major devices opposite interference, existing in inductive coupling channel of automatic locomotive signaling. On the other hand, it is a consequence of the lack of regulatory documentation with uniform established requirements for interference parameters under the influence of which, safety locomotive major devices, primarily built on a relay element base, shall provide for regular operation. Over the past decades, numerous and different by their technical essence attempts have been made to resolve these antagonistic contradictions. This work is one of the first attempts to generalize and analyze the results of pursued research and developments. The work is based on the results of a patent study conducted by the authors in order to identify trends in technical measure development to improve noise immunity in operation of safety locomotive major devices. On their basis, the authors proposed, described in detail and substantiated main technical methods for reducing failure number in the operation of safety locomotive major devices. The obtained results may be of interest to specialists involved in technical servicing, repairment, development and improvement of safety locomotive major devices and will be used further in the development of the theory of locomotive automatic signaling numerical code.

Electromechanical Coupling and Application of High-Frequency Communication Antenna Channel Capacity

The next-generation communication base station antennas represented by phased array antennas are towards high frequency, high gain, high density, and high pointing accuracy. The influence of mechanical structure factors on communication system channel quality is obviously increasing, and the electromechanical coupling problem is becoming more prominent. To effectively guarantee the realization of 5G/6G communication in complex working environments and accelerate the commercial process of future communication systems, an electromechanical coupling channel capacity model is established in comprehensive consideration of the positional shift, attitude deflection, and temperature change of the communication base station phased array antennas. It can be used to rapidly evaluate the communication index degradation of RF devices within the heating environment. Moreover, a sensitivity model of the electric field strength and array antenna channel capacity to the random position error of each element is constructed. The influence of the random positioning error of each element on the communication indicators is analyzed and compared under different working conditions. The simulation results show that the proposed model can effectively provide a theoretical basis and guiding role for the design and manufacture of high-frequency array base station antennas.

Structural Advances in Voltage-Gated Sodium Channels.

Voltage-gated sodium (NaV) channels are responsible for the rapid rising-phase of action potentials in excitable cells. Over 1,000 mutations in NaV channels are associated with human diseases including epilepsy, periodic paralysis, arrhythmias and pain disorders. Natural toxins and clinically-used small-molecule drugs bind to NaV channels and modulate their functions. Recent advances from cryo-electron microscopy (cryo-EM) structures of NaV channels reveal invaluable insights into the architecture, activation, fast inactivation, electromechanical coupling, ligand modulation and pharmacology of eukaryotic NaV channels. These structural analyses not only demonstrate molecular mechanisms for NaV channel structure and function, but also provide atomic level templates for rational development of potential subtype-selective therapeutics. In this review, we summarize recent structural advances of eukaryotic NaV channels, highlighting the structural features of eukaryotic NaV channels as well as distinct modulation mechanisms by a wide range of modulators from natural toxins to synthetic small-molecules.

Ligand Modified and Light Switched On/Off Single-Chain Magnets of {Fe 2 Co} Coordination Polymers via Metal-to-Metal Charge Transfer

Ligand Modified and Light Switched On/Off Single-Chain Magnets of {Fe ₂ Co} Coordination Polymers via Metal-to-Metal Charge Transfer

Rotational state specific dissociation dynamics of D2O via the C̃(010) state: The effect of bending vibrational excitation.

The rotational state resolved photodissociation dynamics of D2O via the C̃(010) state has been investigated by using the D-atom Rydberg tagging time-of-flight technique combined with a tunable vacuum ultraviolet light source. The D-atom action spectrum of the C̃(010) ← X̃(000) band and the corresponding time-of-flight (TOF) spectra of D-atom photoproducts formed following the excitation of D2O to individual rotational transition have been measured. By comparison with the action spectrum of the C̃(000) ← X̃(000) band, the bending vibrational constant of the C̃ state for D2O can be determined to be v2 = 1041.37 ± 0.71cm-1. From the TOF spectra, the product kinetic energy spectra, the vibrational state distributions of OD products, and the state resolved anisotropy parameters have been determined. The experimental results indicate a dramatic variation in the OD product state distributions for different rotational excitations. This illuminates that there are two distinctive coupling channels from the C̃(010) state to the low-lying electronic states: the homogeneous electronic coupling to the Ã1B1 state, resulting in vibrationally hot OD(X) products, and the Coriolis-type coupling to the B̃1A1 state, producing vibrationally cold but rotationally hot OD(X) and OD(A) products. Furthermore, the three-body dissociation channel is confirmed, which is attributed to the C̃ → 1A2 or C̃ → Ã pathway. In comparison with the previous results of D2O photolysis via the C̃(000) state, it is found that the v2 vibration of the parent molecule enhances both the vibrational and rotational excitations of OD products.

Desynchronization of thermosensitive neurons by using energy pumping

A temperature-dependent nonlinear circuit can be mapped into an equivalent thermosensitive neuron model and then the main dynamical properties of neural activities can be reproduced. A thermistor is connected to different branch circuits of the FHN (FitzHugh–Nagumo) neural circuit, and different thermosensitive neuron models are obtained by applying scale transformation on the parameters and physical variables. The dynamics of the thermosensitive neurons is dependent on the temperature greatly, and synchronization stability between these neurons is investigated by selecting different kinds coupling channels. The reliability of this coupling scheme is mainly controlled by the physical properties of the electronic components in the coupling channels. A capacitor (and induction coil) can be used to connect nonlinear circuits and field coupling is activated to pump field energy for realizing synchronization. This kind of field coupling shows some advantage than the known voltage coupling via resistor connection because of no consumption of Joule heat and the coupling channel is adjustable. The results confirmed that two identical temperature-sensitive neurons can be coupled to reach complete synchronization by regulating the physical parameters in the coupling channel, and energy pumping along the coupling channel is decreased to zero under complete synchronization. For two thermosensitive neurons with parameter mismatch and diversity in temperature, synchronization approach becomes difficult and the energy pumping in the coupling channel is continued under phase lock. Its biophysical significance is that diversity in excitability and difference in channels makes thermosensitive neurons become much different, and the occurrence of bursting synchronization and seizure can be prevented completely.

Long-term hillslope erosion and landslide–channel coupling in the area of the catastrophic Wenchuan earthquake

Approximately 200,000 landslides were triggered by the 2008 Wenchuan earthquake and subsequent strong rainfall events, and the amount of landslide sediment delivered to the channels within catchments depended on the amount of landslide debris generated by the earthquake and the amount of post-earthquake rainfall. To better understand long-term hillslope erosion and the long-term changes in landslide–channel coupling, this study quantifies the coupling degree of landslide–channel by defining a landslide-channel coupling index (LCCI) and estimates the long-term hillslope erosion driven by landslides within 12 debris flow basins. We track landslide activity using multiyear imagery from 2008 to 2019, and the landslide ratio, landslide new regeneration ratio, and landslide reactivated ratio indicate that the overall landslide activity decayed following the Wenchuan earthquake. The calculation results of the coupling index illustrate that the coupling degree of landslide–channel in the study area follows a power law trend of decay over time. However, due to the influence of landslide activity, the coupling index decreased significantly in the first 5 years after the Wenchuan earthquake and then decreased slowly. The hillslope erosion driven by landslides is estimated using a conservative statistical model. The result shows that the landslide-driven hillslope erosion has decayed following a power law, and elevated levels of erosion may last for an unexpectedly long period. In addition, the landslide–channel coupling degree affects the movement of landslide sediment to channels. While the coupling degree of landslide–channel and the amount of landslide sediment supplied to the channels have decreased significantly in recent years, abundant landslide sediment could still be delivered to the channels when strong rainfall occurs in this region. Furthermore, a considerable amount of sediment appears to remain within the tributary channels and trunk channels, which means the activity of debris flow may last longer period than hillslope erosion.

Role of positive transfer Q values in fusion cross sections for O18+W182,184,186 reactions

Background: The relevance of including channel coupling effects in the form of target deformation and vibration in fusion reactions has been well established. Many reactions with positive $Q$ values for neutron transfer show enhancement in sub-barrier fusion cross sections. However, there are exceptions to these cases.Purpose: We aim to make a comprehensive list of factors influencing the sub-barrier fusion enhancement in systems with neutron transfer channels having positive $Q$ values.Method: Evaporation residue cross sections were measured for $^{18}\mathrm{O}+^{182,184,186}\mathrm{W}$ reactions in the energy range $68--104$ MeV in the laboratory frame, using a recoil mass spectrometer.Results: Inclusion of deformation of target and projectile low-level excitations in the coupled channels calculations explains the measured fusion excitation functions of $^{18}\mathrm{O}+^{182,184,186}\mathrm{W}$ reactions.Conclusions: Considering that all the targets have similar deformation, and comparing with $^{16}\mathrm{O}+^{182,184,186}\mathrm{W}$ reactions having negative $2n$ transfer $Q$ values, we can conclude that the positive $Q$ values of neutron transfer channels have no effect on the observed fusion cross sections of $^{18}\mathrm{O}+^{182,184,186}\mathrm{W}$ reactions.

Interdash Coupling within Dense Ensembles of Quantum Dashes: Comparison of InAs /( In , Al , Ga ) As / InP and InAs /( In , Al ) As

Lasers, light-emitting diodes, and other optoelectronic devices employing $\mathrm{In}\mathrm{As}$/$\mathrm{In}\mathrm{P}$ quantum dots (QDs) instead of quantum wells (QWs) as their active parts benefit from the quasi-zero-dimensional (0D) density of states while maintaining the emission at the communication-relevant range of $1.55\phantom{\rule{0.2em}{0ex}}\ensuremath{\mu}\mathrm{m}$. However, for certain application purposes, the substitution of QWs with QDs is advantageous only if QDs can either be treated as isolated objects or exhibit quantum-mechanical coupling between deeply confined states. Here, we compare two material systems of $\mathrm{In}\mathrm{As}$/($\mathrm{In}$,$\mathrm{Al}$,$\mathrm{Ga}$)$\mathrm{As}$/$\mathrm{In}\mathrm{P}$ and $\mathrm{In}\mathrm{As}$/($\mathrm{In}$,$\mathrm{Al}$)$\mathrm{As}$/$\mathrm{In}\mathrm{P}$ elongated QDs (quantum dashes, QDashes) of comparable surface densities and interdash distances. We investigate the presence and type of coupling between QDashes, focusing on the direct tunnel coupling for both types of carriers manifested already at low temperature. In the time-resolved photoluminescence (PL) experiment, we observe a significant dispersion of the PL decay time for $\mathrm{In}\mathrm{As}$/($\mathrm{In}$,$\mathrm{Al}$,$\mathrm{Ga}$)$\mathrm{As}$ QDashes, resulting from the migration of carriers from high- to low-energy QDashes due to substantial tunnel coupling. In the case of $\mathrm{In}\mathrm{As}$/($\mathrm{In}$,$\mathrm{Al}$)$\mathrm{As}$ QDashes, the dispersionless time dependence points toward the absence of such coupling. We confirm this interpretation with multiband $\mathbit{k}\ensuremath{\cdot}\mathbit{p}$ calculations. We check that the proposed coupling scenario is possible and show its much higher probability for $\mathrm{In}\mathrm{As}$/($\mathrm{In}$,$\mathrm{Al}$,$\mathrm{Ga}$)$\mathrm{As}$ than for $\mathrm{In}\mathrm{As}$/($\mathrm{In}$,$\mathrm{Al}$)$\mathrm{As}$ QDashes. Finally, in temperature-dependent PL, we observe the redistribution of holes among QDashes via thermal excitation to wetting-layer states for both systems, constituting an additional interdash coupling channel at elevated temperatures. Our results indicate that the $\mathrm{In}\mathrm{As}$/($\mathrm{In}$,$\mathrm{Al}$)$\mathrm{As}$ QDash system is preferential for optoelectronic applications where QD isolation is highly sought after, whereas $\mathrm{In}\mathrm{As}$/($\mathrm{In}$,$\mathrm{Al}$,$\mathrm{Ga}$)$\mathrm{As}$ QDashes exhibit quantum-mechanical coupling between deeply confined states.

Channel Coupling Dynamics of Deep-Lying Orbitals in Molecular High-Harmonic Generation.

Investigation on structures in the high-harmonic spectrum has provided profuse information of molecular structure and dynamics in intense laser fields, based on which techniques of molecular ultrafast dynamics imaging have been developed. Combining abinitio calculations and experimental measurements on the high-harmonic spectrum of the CO_{2} molecule, we find a novel dip structure in the low-energy region of the harmonic spectrum which is identified as fingerprints of participation of deeper-lying molecular orbitals in the process and decodes the underlying attosecond multichannel coupling dynamics. Our work sheds new light on the ultrafast dynamics of molecules in intense laser fields.

Role of e-commerce and resource utilization for sustainable business development: goal of economic recovery after Covid-19

This study seeks to granularly document the fundamental aspects of the pandemic and its effect on the global scale and environmental steadiness. Structural equation modeling (SEM) is therefore utilized to analyze these constructs. The study results show that the pathway coefficient for the parameters, such as health awareness, naturalism, mediation, personal development, sustainability, sociability, empathy, and cooperation, illustrates that the parameters directly impact pandemic control and management. At the same time, the lockdown and social distance rules attain dire consequences on the “conventional” retail property sector. It might speed up the evolution procedure of different conduits retail plus the channel coupling performance of physical stores and, hence, cause changes in urban areas–retail sector. The pandemic isn’t necessarily leading to the shutdown of retail stores. Nonetheless, it might have a meaningful effect on the retail estate enterprise business. The results show a requirement for the rapid physical shop repositioning performance of different channels firms. The study presents a meaningful understanding and demonstrates many consequences for the retailers, Landlords, and equally policy crafting components tackling urban regeneration plus local economic advancement within the post-covid phase.

Adenovirus increases arrhythmia susceptibility during acute cardiac infection

Myocarditis is responsible for 42% of sudden cardiac death in young adults, yet mechanisms underlying virally induced arrhythmia remain elusive. Adenovirus is a leading etiological agent of myocarditis but species‐specificity has limited development of animal disease models. Normal electrical impulse propagation in the heart is achieved through intercellular coupling via gap junctions, composed primarily of connexin43 (Cx43). Changes in Cx43 expression, localization, and/or function underlie the arrhythmias of sudden cardiac death. Given that gap junctions also propagate innate and adaptive antiviral immune responses, we hypothesized that adenovirus would target Cx43 to facilitate replication. Our prior work has demonstrated that Cx43 expression and function are indeed reduced rapidly during adenoviral infection limiting gap junction communication in human epithelial and cardiac cells. We are now employing a recently described cardiotropic strain of mouse adenovirus, MAdV‐3, to develop our work into whole animal studies and investigate virally‐induced alterations in cardiac electrophysiology and the molecular mechanisms of the resulting arrhythmogenic substrate. Adult mice were inoculated with MAdV‐3 and sampled after 7 days to model acute cardiac infection. We find MAdV‐3 viral genomes are specifically enriched in heart tissue, confirming cardiotropism. No cardiomyopathy was apparent by echocardiography or histopathology, consistent with human acute myocarditis patients. We find reductions in cardiac ion channel and connexin mRNA transcript levels after infection, and at the protein level, Cx43 is phosphorylated at residues known to reduce function. Ex vivo optical mapping experiments illustrate decreased conduction velocity in infected hearts. Turning to primary adult mouse cardiomyocytes, we detect prolonged action potential duration and impaired K+ current in infected cells by patch clamping. Confocal and super‐resolution localization microscopy of infected cardiac tissue and isolated cardiomyocytes reveals remodeling of gap junctions with alterations in complexing with scaffolding proteins and other ion channels at the cell‐cell junction. Finally, employing human iPSC‐derived cardiomyocytes and human adenovirus type‐5, we find increased Cx43 phosphorylation and, using optical mapping, perturbation of intercellular coupling during infection, just as we see with MAdV‐3. Our data demonstrate that reduced cellular coupling and ion channel function during adenoviral infection generates an arrhythmogenic substrate prior to an appreciable immune response or cardiomyopathy development. MAdV‐3 infection therefore provides a novel model of cardiac infection and myocarditis and provides physiologically relevant insight into mechanisms of virally‐induced arrhythmias.

Two-Channel Charge-Kondo Physics in Graphene Quantum Dots.

Nanoelectronic quantum dot devices exploiting the charge-Kondo paradigm have been established as versatile and accurate analogue quantum simulators of fundamental quantum impurity models. In particular, hybrid metal–semiconductor dots connected to two metallic leads realize the two-channel Kondo (2CK) model, in which Kondo screening of the dot charge pseudospin is frustrated. In this article, a two-channel charge-Kondo device made instead from graphene components is considered, realizing a pseudogapped version of the 2CK model. The model is solved using Wilson’s Numerical Renormalization Group method, uncovering a rich phase diagram as a function of dot–lead coupling strength, channel asymmetry, and potential scattering. The complex physics of this system is explored through its thermodynamic properties, scattering T-matrix, and experimentally measurable conductance. The strong coupling pseudogap Kondo phase is found to persist in the channel-asymmetric two-channel context, while in the channel-symmetric case, frustration results in a novel quantum phase transition. Remarkably, despite the vanishing density of states in the graphene leads at low energies, a finite linear conductance is found at zero temperature at the frustrated critical point, which is of a non-Fermi liquid type. Our results suggest that the graphene charge-Kondo platform offers a unique possibility to access multichannel pseudogap Kondo physics.

Effect of Shapes Degrees of Freedom on the Fusion Cross-Sections of 16O + 154Sm and 18O + 148Nd

The fusion dynamics of 16O + 154Sm and 18O+148Nd reactions has been investigated to observe the effect of shape degree of freedom on the fusion cross-section using the coupled channel (CC) calculations. The one dimentional barrier penetration model (1-D BPM) is observed to underestimate the experimental data mainly at below barrier energies. The coupled channel calculations, including target projectile excitations with 1 phonon of vibrational state and 2+ rotational state of target, reproduce the experimental fusion cross-section for 16O + 154Sm reaction at below barrier energies, while show some discrepancy for 18O+148Nd reaction. This discrepancy for 18O+148Nd reaction can be addressed with the inclusion of low-lying states with neutron transfer channels and the neck-formation.

Forecasts of MJO during DYNAMO in a Coupled Tropical Channel Model: Impact of Planetary Boundary Layer Schemes

It is challenging to predict the eastward-propagating Madden–Julian Oscillation (MJO) events across the Maritime Continent (MC) in models. We constructed an air–sea coupled numerical weather prediction model—a tropical channel model—to investigate the role of the planetary boundary layer (PBL) scheme on eastward-propagating and non-propagating MJO precipitation events during the Dynamics of the MJO (DYNAMO) campaign period. Analysis of three hindcast experiments with different PBL schemes illustrates that the PBL scheme is crucial to simulating the eastward-propagating MJO events. The experiment with the University of Washington (UW) PBL scheme can predict the convection activity over the MC due to a good representation of moist static energy (MSE) tendency relatively well. The horizontal advection and the upward transport of moisture from the PBL to the free atmosphere play a major role in the MSE tendency ahead of MJO convection. The difference in the meridional component of MSE advection accounts for the different MSE budgets in the three hindcast experiments. A well-simulated meridional advection can transport the meridional water vapor to moisten the MC. Our results suggest that a proper PBL scheme with better simulated meridional water vapor distribution is crucial to predicting the eastward propagation of MJO events across the MC in the tropical channel model.

From Dynamic Superwettability to Ionic/Molecular Superfluidity.

Life systems present ultralow energy consumption in high-efficiency energy conversion, information transmission, and biosynthesis. The total energy intake of the human body is about 2000 kcal/day to maintain all of our activities, which is comparable to a power of ∼100 W. The energy required for the brain to work is equivalent to ∼20 W, and the rest of the energy (∼80 W) is used for other activities. All in vivo biosyntheses take place only at body temperature, which is much lower than that of in vitro reactions. To achieve these ultralow energy-consumption processes, there should be a kind of ultralow-resistivity matter transport in nanochannels (e.g., ionic and molecular channels), in which the directional collective motion of ions or molecules is a necessary condition rather than traditional Newton diffusion. The directional collective motion of ions and molecules is considered to be ionic/molecular superfluidity. The driving force of ionic/molecular superfluidity formation requires two necessary conditions: (1) Ions or molecules are confined at a certain distance (e.g., approximately twice Debye length (2λD) for ions or twice the van der Waals equilibrium distance (2d0) for molecules). (2) When the attractive potential energy (E0) is stronger than the thermal noise (kBTc), ionic/molecular superfluidity can be formed. The concept of ionic/molecular superfluidity will promote the understanding of energy conversion with ultralow energy consumption in biological systems. The swing of an eel's body generating electricity and cardiac resuscitation denote the conversion from mechanical energy to electrical energy, and mechanical modulation might result in a coherent resonance of ionic motion. The coherent resonance of Ca2+ in myocardium cells can induce a heartbeat, realizing the conversion from the electrical energy to the mechanical energy of a biological system. The macroscopic quantum state of ion channels is considered to be a carrier of neural information, and the environment field might play a significant role in regulating the macroscopic quantum states of various ion channels. In the biological ion channels system, the coupling of ion channels and their released photons might induce an environment wave which in turn regulates the ion oscillations in the channels to a coherent state. The states of decoherence and coherence might correspond to the states of sleep and action. We also demonstrated the decomposition of ATP to ADP released photons with a frequency of ∼34 THz, which could further drive DNA polymerization in the nanocavity of DNA polymerase. The photochemical (mid- and far-IR) reaction might be the driving force in high-efficiency biosynthesis. Quantized syntheses resonantly driven by multiple mid- and far-IR photons could be further designed in a tubular reactor with membranes of different microporous structures to achieve a high-efficiency synthesis with a low energy consumption. Finally, we point out that the Bose-Einstein condensate potentially widely exists. We expect that this Account will provide new ideas for the key problem in life science: how can life systems present ultralow energy consumption in high-efficiency energy conversion, information transmission, and biosynthesis?

Dynamics and physiological meaning of complexes between ion channels and integrin receptors: the case of Kv11.1.

The cellular functions are regulated by a complex interplay of diffuse and local signals. Studying the latter is challenging, but experimental work in cell physiology has led to recognize that understanding a cell's dynamics requires a deep comprehension of local fluctuations of cytosolic regulators. Macromolecular complexes are major determinants of local signaling. Multienzyme assemblies limit the diffusion restriction to reaction kinetics by direct exchange of metabolites. Likewise, close coupling of ion channels and transporters modulates the ion concentration around a channel mouth or transporter binding site. Extreme signal locality is brought about by conformational coupling between membrane proteins, as is typical of mechanotransduction. A paradigmatic case is integrin-mediated cell adhesion. Sensing the extracellular microenvironment and providing an appropriate response are essential in growth and development and have innumerable pathological implications. The process involves bidirectional signal transduction by complex supramolecular structures that link integrin receptors to ion channels and transporters, growth factor receptors, cytoskeletal elements, and other regulatory elements. The dynamics of such complexes are only beginning to be understood. A thoroughly studied example is the association between integrin receptors and the voltage-gated K+ channels Kv11.1. These channels are widely expressed in early embryos, where their physiological roles are poorly understood and apparently different from the shaping of action potential firing in the adult. Hints about these roles come from studies in cancer cells, where Kv11.1 is often overexpressed and appears to reassume functions it presumably exerts during embryogenesis, such as controlling cell proliferation/differentiation, apoptosis, and migration. Kv11.1 is implicated in these processes through its linking to integrin subunits, which in turn regulates channel expression. Specific cellular functions, such as proliferation and migration, appear to be modulated by distinct conformational states of the channel (e.g., open and closed), whose balance is affected by the link with integrin subunits.

Screening of Relevant Metabolism-Disrupting Chemicals on Pancreatic β-Cells: Evaluation of Murine and Human In Vitro Models.

Endocrine-disrupting chemicals (EDCs) are chemical substances that can interfere with the normal function of the endocrine system. EDCs are ubiquitous and can be found in a variety of consumer products such as food packaging materials, personal care and household products, plastic additives, and flame retardants. Over the last decade, the impact of EDCs on human health has been widely acknowledged as they have been associated with different endocrine diseases. Among them, a subset called metabolism-disrupting chemicals (MDCs) is able to promote metabolic changes that can lead to the development of metabolic disorders such as diabetes, obesity, hepatic steatosis, and metabolic syndrome, among others. Despite this, today, there are still no definitive and standardized in vitro tools to support the metabolic risk assessment of existing and emerging MDCs for regulatory purposes. Here, we evaluated the following two different pancreatic cell-based in vitro systems: the murine pancreatic β-cell line MIN6 as well as the human pancreatic β-cell line EndoC-βH1. Both were challenged with the following range of relevant concentrations of seven well-known EDCs: (bisphenol-A (BPA), bisphenol-S (BPS), bisphenol-F (BPF), perfluorooctanesulfonic acid (PFOS), di(2-ethylhexyl) phthalate (DEHP), cadmium chloride (CdCl2), and dichlorodiphenyldichloroethylene (DDE)). The screening revealed that most of the tested chemicals have detectable, deleterious effects on glucose-stimulated insulin release, insulin content, electrical activity, gene expression, and/or viability. Our data provide new molecular information on the direct effects of the selected chemicals on key aspects of pancreatic β-cell function, such as the stimulus-secretion coupling and ion channel activity. In addition, we found that, in general, the sensitivity and responses were comparable to those from other in vivo studies reported in the literature. Overall, our results suggest that both systems can serve as effective tools for the rapid screening of potential MDC effects on pancreatic β-cell physiology as well as for deciphering and better understanding the molecular mechanisms that underlie their action.

Synthesis Based on Linearization of Vector Speed Control of an Induction Motor without a Speed Sensor

The aim of the work was parametric synthesis of vector sensorless (i. e. without speed sensor) control of an electric drive with an induction motor. The structure of the system is based on the application of an adaptive model for estimating the rotor flow coupling vector and velocity. The speed is estimated by the mismatch of the real stator current and the current value calculated in the model. Stability is guaranteed in this well-known structure, obtained on the basis of Lyapunov functions, but it remains problematic to calculate the parameters of regulators and an adaptive model to ensure high-quality dynamics of the system. For a vector control system of an induction electric motor without a speed sensor with an adaptive model, a linearized structure in a synchronously rotating coordinate system was proposed. This makes it possible to calculate control parameters using the modal control method to ensure quality indicators in each of the closed circuits of the system. Such parametric synthesis is based on the assumption that the flow coupling of the rotor is maintained constant, and therefore the mutual influence of the flow coupling and torque control channels can be neglected. The calculation of the parameters of control (regulators and the adaptation channel) is based on the method of assigning the roots of characteristic contour polynomials in such a way that each internal contour has a higher speed than the external one with respect to it. The method is approximate, but it makes it possible to take into account the main cause-and-effect relationships in dynamics and obtain simple calculation expressions. The simulation of the system was carried out using a simulation model that takes into account the digital software-algorithmic method for generating a microcontroller control signal, as well as electromagnetic processes under conditions of pulse-width modulation in an electric energy converter and an electric motor, the use of the values of the rotor flow coupling vector estimated by the model in coordinate transformations of the system, the formation of a spatial vector of the converter voltage. The analysis of the synthesized speed control system by the simulation method has confirmed the effectiveness of the proposed method of parametric synthesis and the acceptable accuracy of speed estimation.